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Transparent wood

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Plastics are pretty much everywhere in the modern world including places we want them to be and places where we don’t.  Conventional plastics are not biodegradable and instead cause increasing problems wherever they end up after their useful life.  As a result, there are global efforts to find environmentally friendly replacements for petroleum-based plastics.

An interesting candidate for replacing many types of plastic is transparent wood.  Transparent wood is a man-made material derived from natural wood.  Wood has three components:  cellulose, hemicellulose, and lignin.  Transparent wood is created by removing the lignin and hemicellulose, leaving behind a porous, paper-like network of cellulose.  It is transparent but lacks structural strength.  In the past, clear materials like epoxies have been added to produce a strong, transparent material:  transparent wood.  But because of the epoxy – itself a form of plastic – the resultant material was non-biodegradable.

Researchers at Kennesaw State University in Georgia have developed a method for producing transparent wood that replaces epoxies with an egg white and rice extract mixture along with a curing agent called diethylenetriamine.  The end product is a semi-transparent form of wood that is biodegradable. 

The researchers also incorporated silver nanowires into samples of their transparent wood.  This enabled the wood to conduct electricity and could be useful in wearable sensors or as coatings for solar cells.  There is additional research needed to improve the properties of this transparent wood, but a plastic replacement made from natural and inexpensive materials could be quite valuable.

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Making sturdy, semi-transparent wood with cheap, natural materials

Photo, posted August 1, 2017, courtesy of NOAA Marine Debris via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Hurricanes and wildfires

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Early March saw more than 200 wildfires break out in the southeastern U.S. – a busy start to the region’s annual fire season.  One fire in the Carolina Forest near Myrtle Beach scorched over 2,000 acres over a two-week period and firefighters were busy containing it and many other blazes.

Strong winds and an unusually long dry period have made fires more likely to ignite and be spread.  Lightning strikes, power line sparking, backyard fire pits and leaf burning all can lead to wildfires under these conditions.

A weather disaster last year may be helping to make this fire season worse than usual.  Hurricane Helene ravaged the Southeast last September, dumping more than a foot of rain in some locations and knocking over hundreds of thousands of acres of trees across the region.

Lots of dead trees lying on the ground allow sunlight to reach the ground and dry out all the biomass, including the trees.  All of this desiccated plant material acts as kindling, providing fuel for wildfires.  Fallen trees can be a fire nuisance for years after a hurricane, especially in the Southeast, where dried out pine needles are highly combustible.  All it takes is an ignition.

In addition, all the fallen trees represent an access issue for firefighters as the logs block roads needed to reach the fires.

Research has shown that climate change is fueling more intense fires in the West.  Whether the changing climate is having a major effect in the Southeast isn’t clear.  But droughts are expected to become more intense and more frequent in the Southeast because of climate change and that isn’t good news for the likelihood of wildfires.

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How Hurricanes Can Fuel Wildfires in the Southeast

Photo, posted March 5, 2025, courtesy of the U.S. Army National Guard / Roberto Di Giovine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Green grout for stabilizing buildings

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We are all familiar with the grout that is used for tiles in our homes. We are less familiar with grout that is used to stabilize the soil beneath buildings.  Grouting is a process of ground improvement by injecting materials that can fill voids and cracks, strengthen and increase the bearing capacity of soil, and reduce permeability.

Traditional grouting methods have environmental downsides.  Most often, silica-based chemical grouts are used, and they are produced through energy-intensive processes that contribute substantially to carbon dioxide emissions.  As is the case for all materials and practices of the construction industry, developing sustainable, low-emission alternatives to conventional grouting materials has become an important priority.

Researchers from the Shibaura Institute of Technology in Japan have developed an innovative new grout material called Colloidal Silica Recovered from Geothermal Fluids.  This grout material enhances soil stabilization and simultaneously reduces the environmental impact of geothermal energy harvesting.

Geothermal energy production generates large amounts of silica-rich waste fluids which creates challenges for its maintenance and disposal.  The new grout repurposes this waste material thereby transforming an industrial byproduct into a valuable construction material.

The new grout material is particularly valuable in earthquake-prone regions, where soil stabilization is essential in preventing structural damage during seismic events.  In addition, the grout’s superior water-sealing properties makes it ideal for underground construction projects like tunnels, subways, and basements.  The new grout in an important step for the construction industry’s efforts to achieve carbon neutrality.

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From Waste to Wonder: Revolutionary Green Grout for Sustainable Construction Practices

Photo, posted July 8, 2011, courtesy of MTA Construction & Development Mega Projects via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A better way to produce green hydrogen

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Hydrogen has great potential as a fuel and an energy carrier for many applications.  Burning it or consuming it in fuel cells does not produce carbon emissions.  As a result, there has long been the vision for a future hydrogen economy.  Whether the hydrogen economy would ever come about given how various other technologies have evolved over time is questionable.  But regardless, hydrogen is valuable for many industrial and commercial applications including the manufacture of ammonia and the refining of metals.

Hydrogen is produced in industrial quantities from natural gas by a carbon-dioxide-producing process known as methane-steam reforming.  To take its place as a green energy source, hydrogen needs to be produced by splitting water into its constituent oxygen and hydrogen components by the process of electrolysis. 

The problem is economic.  Methane-steam reforming produces hydrogen at a cost of about $1.50 per kilogram.  Green hydrogen costs about $5 a kilogram.

Researchers at Oregon State University have developed a new photocatalyst that enables the high-speed, high-efficiency production of hydrogen.  The material, called RTTA, is a metal organic framework containing ruthenium oxide and titanium oxide.  Ruthenium oxide is expensive, but very little is needed.  For industrial applications, if the catalyst shows good stability and reproducibility, the cost of the small amount of this exotic material becomes less important.

The photocatalyst, when exposed to sunlight, quickly and efficiently splits water yielding hydrogen.  The Oregon State discovery has real potential.

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Oregon State University research uncovers better way to produce green hydrogen

Photo, posted July 7, 2023, courtesy of Bill Abbott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Increasing plastic recycling

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Recycling plastic is a complicated matter.  There are many different types of plastic and knowing which things are made of which type isn’t easy.  There are increasingly widespread recycling systems across the U.S., but the actual rates of recycling have been described as “abysmal”.

The plastic commonly used in beverage bottles is polyethylene terephthalate, or PET.  The present nationwide rate of recycling PET is about 24% and has been about at that level for a decade.

A new study by MIT has found that with a nationwide bottle deposit program, the rates could increase to 82%.  At that level, nearly two-thirds of all PET bottles could be recycled into new bottles at a net cost of just a penny a bottle.

The study looked at PET bottle collection and recycling rates in different states as well as other nations with and without bottle deposit policies, and with and without curbside recycling programs.  The study is the first to look in detail at the interplay between public policies and the detailed end-to-end aspects of the packaging, production and recycling market.

Recycling of PET is highly successful in terms of quality.  New products made from all-recycled material is virtually indistinguishable from virgin material.  The crucial bottleneck is the collection of sufficient amounts of material to meet the needs of processing plants.  So, the conclusion of the study is that with the right policies in place, significant improvements can be made.  Several European countries manage to collect more than 90% of PET bottles for recycling.  So, it can be done.

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How to increase the rate of plastics recycling

Photo, posted August 10, 2013, courtesy of Lisa Risager via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seashells inspire better concrete

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Mother of pearl – also known as nacre – is a natural material found in certain seashells such as those of oysters and abalone.  On the microscopic level, it consists of hexagonal tablets of the hard mineral aragonite glued together by a soft biopolymer.  The aragonite gives nacre its strength, and the biopolymer adds flexibility and crack resistance. 

Scientists at Princeton University have developed innovative composite materials inspired by nacre by utilizing conventional construction materials like Portland cement paste combined with a limited amount of polymer.  The new material consists of alternating layers of cement paste sheets with the highly stretchable polymer polyvinyl siloxane.

The materials were subjected to bending tests to evaluate crack resistance or fracture toughness.  Three different versions of the material were tested that used different ways of interposing the polymer layers.  The new materials were compared with similar structures composed entirely of cement.

The concrete-only samples were brittle, breaking suddenly and completely upon reaching their failure point.  The samples with alternating cement and polymer layers demonstrated increased ductility and resistance to cracking. 

By fully mimicking the structure of nacre – using completely separated hexagonal cement tablets – the researchers demonstrated materials with 19 times the ductility and 17 times the fracture toughness of cement while retaining nearly the same strength as solid cement samples.

Engineered materials inspired by nature could eventually help increase the durability of a wide range of brittle ceramic materials, from concrete to porcelain.

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From seashells to cement, nature inspires tougher building material

Photo, posted January 2, 2016, courtesy of Yantra via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling cement

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Concrete is the second-most-used material on the planet.  Only water is used more.  Producing concrete is responsible for 7.5% of human-produced carbon dioxide emissions.  So, finding a cost-effective way to reduce these emissions is a major challenge in the face of ever-growing global demand for concrete.

Researchers at Cambridge University have found that used cement is an effective substitute for lime flux, which is an essential material used in steel recycling that results in a waste product called slag.  When lime is replaced with used cement, the end product instead is recycled cement that can be used to make new concrete.

The process does not add any significant costs to concrete or steel production and significantly reduces the emissions associated with both.

Concrete is made from sand, gravel, water, and cement.  Cement is made by a process called clinkering, in which limestone and other materials are heated to 2,600 degrees Fahrenheit.  The process converts the materials into cement but releases large amounts of CO2 as limestone decarbonates into lime. 

Cambridge researchers found that using cement clinker and iron oxide instead of lime works well in steel recycling.  Crushing old concrete and taking out the sand and stone results in a cement that is reactivated by the recycling furnace to produce a material with excellent properties. 

Recent tests by the Materials Processing Institute showed that recycled cement can be produced at scale in an electric arc furnace.  Ultimately, this method could produce zero emission cement if the electricity for the furnace comes from renewable sources.

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Cement recycling method could help solve one of the world’s biggest climate challenges

Photo, posted July 18, 2011, courtesy of Kenta Mabuchi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic food packaging

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Reducing the use of plastic is an important environmental goal.  Plastic is made from fossil fuels and plastic pollutes the land and the oceans.  It is estimated that 40% of plastic waste comes from packaging.  Plastic packaging is extremely common in the supermarket and there is a growing desire to reduce its use.  But it isn’t that easy.

Plastic packaging works well to slow the decay of vegetables and fruit.  Its use results in less produce being tossed into the garbage, where it creates almost 60% of landfill methane emissions.  In fact, food is the most common material in landfills.  The average American family of four spends $1,500 a year on food that ends up uneaten and nearly half of all household food waste is fruits and vegetables.

Products like bagged salads, berries in plastic clamshells, and plastic sealed potatoes and cucumbers are popular with shoppers because they stay fresh longer.  They are popular with grocers because the items don’t have to be weighed.  But all these things result in plastic waste.  It is a tradeoff that is difficult to make between food quality and safety vs. the environmental harm caused by plastic.

There are a variety of alternatives to plastic packaging of food that are being explored.  They range from biodegradable, organic coatings that can take the place of plastic films, to cardboard and paper produce packaging. 

But practically, there is yet no affordable and biodegradable plastic alternative that keeps fruits and vegetables safe and fresh.  Solving the food packaging problem is not easy.

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So Much Produce Comes in Plastic. Is There a Better Way?

Photo, posted July 1, 2007, courtesy of Brian via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Artificial reefs

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The coral reefs that surround tropical islands are a refuge for a wide variety of marine life and also form a natural buffer against stormy seas.  The changing climate is bleaching coral reefs and breaking them down.  Extreme weather events are becoming more common and are threatening coastal communities with flooding and erosion.

Researchers at MIT are designing architected reefs – sustainable offshore structures that mimic the wave-buffering effects of natural reefs and can also provide habitats for fish and other marine life.

There are already artificial reefs in a number of places used to protect coastlines.  These are typically made from sunken ships, retired oil and gas platforms, and even assemblies of concrete, metal, car tires, and stones.  Generally, it takes quite a lot of material to form an effective barrier to waves.

The MIT group has developed a cylindrical structure surrounded by four rudder-like slats.  Their experiments have shown that when this structure stands in the way of a wave, it efficiently breaks the wave and creates turbulent jets that dissipate the energy in the wave.  The engineers calculated that the new design could reduce as much wave energy as existing artificial reefs but use 10 times less material.

Based on the initial experiments with lab-scale prototypes, these artificial reefs would reduce the energy of incoming waves by more than 95%.

Coral reefs are only found in tropical waters, whereas these artificial reefs don’t depend on temperature and could be placed along any coastline for protection.  In a time of rising seas and increasingly frequent storms, these artificial reefs may be just what coastlines need.

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Artificial reef designed by MIT engineers could protect marine life, reduce storm damage

Photo, posted December 9, 2010, courtesy of Phoenix Wolf-Ray via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Biodegradable microplastics

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Ordinary plastics are not biodegradable, but they are also not indestructible.  Plastics in the environment can break down into tiny fragments – microplastics – and those, unfortunately, are nearly indestructible.  Microplastics have been documented in the oceans and in soil virtually everywhere on Earth including remote frozen wastelands and on top of high mountains.  More recently, they have been found in our own arteries, lungs, and even in placentas.  Microplastic pollution is a very serious problem.

There is considerable ongoing effort to develop biodegradable plastics from non-petroleum sources.  There has been progress but it has not necessarily been aimed at creating bioplastics that do not create microplastic when they break down.

Researchers at the University of California San Diego have developed algae-based polymers that they have shown to degrade when composted.  Recently, in work published in the journal Nature Scientific Reports, they have shown that even fine microparticles of their bioplastic are digested by microbes when placed in a compost.  What remains are the starting plant materials from which the plastic was made.  Products made from this sort of plastic would not only be sustainable beyond their useful lifetime but would also not represent a potential danger to human life.

Creating this eco-friendly alternative to petroleum-based plastic is only the first step toward creating a viable replacement for existing plastics.  It is necessary to be able to use the new material on existing manufacturing equipment and for it to have the same mechanical and thermal properties as the materials it is replacing.  But the researchers are optimistic that this could be a potential solution to an increasingly serious problem.

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Say Hello to Biodegradable Microplastics

Photo, posted January 17, 2018, courtesy of Bo Eide via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric Steel Furnaces | Earth Wise

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Steel was first made thousands of years ago.  The discovery that heating up iron ore in a hot enough charcoal fire could purify the iron into a strong and valuable material was the start of the Iron Age.  In many ways, things have changed very little since then.

Global iron and steel production accounts for 7% of society’s carbon emissions. Making steel generally involves burning coal in a blast furnace to produce the very high temperatures required to turn iron into steel.  The coal is used both as a feedstock and as a fuel.  Steel is made from iron and a substance called coke, which is basically coal that has been carbonized at high temperatures.  Coal itself is burned to provide the high temperatures needed.

A new analysis from the Global Energy Monitor think tank shows that the global steel industry is slowly embracing electric-arc furnaces to produce the necessary heat, which is a cleaner alternative.  The analysis found that 43% of forthcoming steelmaking capacity will rely on electric-arc furnaces, up from 33% last year.

According to the study, the shift to cleaner steel is not happening fast enough.  To meet the emissions reductions goals of the Paris Climate Agreement, electric-arc furnaces must account for 53% of global steelmaking capacity by 2050.  Based on the current plans, those furnaces would only account for 32% of total capacity by that year.

In order to meet these goals, the steel industry will need to retire or cancel about 381 million tons of coal-based manufacturing capacity and add 670 million tons of electric-arc furnace capacity. 

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Steel Industry Pivoting to Electric Furnaces, Analysis Shows

Photo, posted March 3, 2012, courtesy of Jeronimo Nisa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cleaner And Greener Steel | Earth Wise

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Producing construction materials like concrete and steel is a major contributor to greenhouse gas emissions.  Between 7 and 8% of emissions are due to steelmaking alone, which has been done pretty much the same way for more than a century.

Iron ore is smelted with high-carbon fuel and is turned into so-called pig iron in a blast furnace, which creates the key raw material for the steel industry.  The process uses huge amounts of energy (still often generated by burning fossil fuels) and releases carbon dioxide as a byproduct. 

The Department of Energy is sponsoring 40 projects at universities, national laboratories and companies in 21 states aimed at reducing industrial carbon pollution.  Ten of those projects are focused on decarbonizing iron and steel. These initiatives are part of the overall effort to move the nation towards a net-zero emissions economy by 2050.

A team headed by Case Western Reserve University that includes Lawrence Livermore National Laboratory, the University of Arizona, and steel company Cleveland-Cliffs Inc. has developed a promising new zero-carbon, electrochemical process for producing steel.

The process is a novel molten salt electrolysis method that is low-cost, capable of achieving high rates, and uses environmentally benign chemicals.  The process does not use carbon at all.  Using molten salts, electrochemistry can be performed at moderately high temperatures rather than the temperatures of nearly 3000 degrees Fahrenheit used for conventional steelmaking.  The goal is to enable steel production that is both economically viable at an industrial scale and that is environmentally sustainable.

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Case Western Reserve leading research to develop zero-carbon, electrochemical process to produce iron metal as part of U.S. Department of Energy effort

Photo, posted January 11, 2017, courtesy of Kevin Casey Fleming via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Harvesting Water From The Air | Earth Wise

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Engineers at MIT have created a superabsorbent material that can soak up significant amounts of moisture from the air, even in desert-like conditions.

The material is a transparent, rubbery substance made from hydrogel, which is a naturally absorbent material that is already widely used in disposable diapers.  The MIT researchers enhanced the absorbency of hydrogel by infusing it with lithium chloride, which is a type of salt that is a powerful desiccant.

They found that they could infuse hydrogel with more salt than was possible in previous studies.  Earlier studies soaked hydrogels in salty water and waited 24 to 48 hours for the salt to infuse into the gels.  Not much salt ended up in the gels and the material’s ability to absorb water vapor didn’t change much.  In contrast, the MIT researchers let the hydrogels soak up the salt for 30 days and found that far more salt was absorbed into the gel.  The result was that the salt-laden gel could then absorb and retain unprecedented amounts of moisture, even under very dry conditions.

Under very dry conditions of 30% relative humidity, the gels captured 1.79 grams of water per gram of material.  Deserts at night have those levels of relative humidity, so the material is capable of generating water in the desert.

The new material can be made quickly and at large scale.  It could be used as a passive water harvester, particularly in desert and drought-prone regions.  It could continuously absorb water vapor from the air which could then be condensed into drinking water.  The material could also be used in air conditioners as an energy-saving, dehumidifying element.

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This salty gel could harvest water from desert air

Photo, posted July 26, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Concrete And Carbon | Earth Wise

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After water, concrete is the world’s second most consumed material.  It is the cornerstone of modern infrastructure.  Its production accounts for 8% of global carbon dioxide emissions.  The carbon dioxide is a result of chemical reactions in its manufacture and from the energy required to fuel the reactions.

About half of the emissions associated with concrete come from burning fossil fuels to heat up the mixture of limestone and clay that ultimately becomes ordinary Portland cement.  These emissions could eventually be eliminated by using renewable-generated electricity to provide the necessary heat.  However, the other half of the emissions is inherent in the chemical process.

When the minerals are heated to temperatures above 2500 degrees Fahrenheit, a chemical reaction occurs producing a substance called clinker (which is mostly calcium silicates) and carbon dioxide.  The carbon dioxide escapes into the air.

Portland cement is then mixed with water, sand, and gravel to produce concrete.  The concrete is somewhat alkaline and naturally absorbs carbon dioxide albeit slowly.  Over time, these reactions weaken the concrete and corrode reinforcing rebar.

Researchers at MIT have discovered that the simple addition of sodium bicarbonate (aka baking soda) to the concrete mixture accelerates the early-stage mineralization of carbon dioxide, enough to make a real dent in concrete’s carbon footprint.  In addition, the resulting concrete sets much more quickly.  It forms a new composite phase that doubles the mechanical performance of early-stage concrete.

The goal is to provide much greener, and possibly even carbon-negative construction materials, turning concrete from being a problem to part of a solution.

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New additives could turn concrete into an effective carbon sink

Photo, posted April 4, 2009, courtesy of PSNH via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Energy From Rice Straw | Earth Wise

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Rice straw is produced as a byproduct of rice production.  Globally, as much as a billion tons of rice straw is produced each year, three-quarters of it in Asia.  Straw incorporation in soil for fertilization is not practical in most places because with multiple crops per year, there is not enough time for the material to decompose and become good fertilizer.  As a result, open-field straw burning is increasingly the standard practice.

Scientists at Aston University in Birmingham in the UK are embarking on a project to convert rice straw in Indonesia into low-cost energy on a commercial scale.

Indonesia produces 100 million tons of rice waste each year, of which 60% is burned in open fields, causing air pollution. 

The Aston researchers are developing a biomass conversion process based on pyrolysis.  This involves heating the rice straw to high temperatures over 900 degrees Fahrenheit to break it down, producing vapor and solid products.  Both of these things can be used to generate electricity.

A new combustion engine designed by a company called Carnot Limited is capable of converting 70% of the thermal energy extracted from the rice straw into electricity.

Energy extracted in this way could help low and middle-income countries to create their own locally generated energy, thereby reducing emissions, creating jobs, and improving human health.   The biomass electricity is predicted to be cheaper than solar, geothermal, wind, coal, or even subsidized gas-generated power.

The Aston University project will help develop a business model that could support companies and communities to produce local, cheap energy in Indonesia and other countries with biomass capacity. 

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Aston University to help power Indonesia with affordable energy made from rice straw

Photo, posted September 11, 2006, courtesy of Kristen McQuillin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Colorful Solar Panels | Earth Wise

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More and more buildings and public spaces are incorporating solar panels and not only just on rooftops.  Some buildings are incorporating power-generating structures all over their facades.

Using solar panels in this way puts some design constraints on buildings because solar panels are typically a deep black color.  This is because solar panels need to absorb light and making them any other color decreases their ability to do so and generate power.  But the problem is that people don’t necessarily want a black building.

One alternative to traditional solar panel design is to use structural sources of color that include microscopic shapes that only reflect specific light frequencies, like the scales on butterfly wings.  But this approach generally leads to iridescence – which might not be what is wanted – and is often quite expensive to implement.

A team of researchers at a university in Shanghai has now demonstrated a way to give solar panels color that is easy and inexpensive to apply and that does not reduce their ability to produce energy efficiently.

The technique involves spraying a thin layer of a material called a photonic glass onto the surface of solar cells.  The photonic glass is made of a thin, disorderly layer of dielectric microscopic zinc sulfide spheres.  Even though most light can pass through the photonic glass, certain colors are reflected back, depending on the sizes of the spheres.  By varying that size, the researchers created solar panels that were blue, green, or purple with only a very small drop in solar panel efficiency.

The solar panels made this way maintained their color and performance under durability testing.  With this new technology, there may soon be colorful solar panels on our buildings.

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Colorful solar panels could make the technology more attractive

Photo, posted December 15, 2021, courtesy of Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Cheap Material For Carbon Capture | Earth Wise

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The recently passed Inflation Reduction Act includes significant support for carbon capture technologies. Eliminating fossil fuel burning is essential for halting climate change, but in the interim, methods for capturing emissions of carbon dioxide and either storing it or turning it into usable products are increasingly necessary.

There are a variety of techniques being developed for carbon capture but at this point, none of them are commercially viable.  The best technique in use today involves piping flue gases through chemicals called liquid amines, which bind CO2.  The process requires large amounts of energy to release the bound carbon dioxide so it can be concentrated and stored.  As a result, it is complicated and expensive.

Researchers at UC Berkeley, Stanford, and Texas A&M University have developed a carbon capture method using melamine, which is an inexpensive polymer used to make Formica, as well as low-cost dinnerware, industrial coatings, and other plastics.  Porous melamine itself adsorbs CO2 to a limited extent.  But the researchers discovered that adsorption could be much improved by adding the chemical DETA (diethylenetriamine) to bind the CO2.  In addition, adding cyanuric acid increased the melamine pore size and radically improved CO2 capture efficiency even more.

The result is a material that is more efficient even than exotic carbon capture materials like metalorganic frameworks and is much cheaper and easier to make. The researchers aim to design equipment that can used in industrial facilities, attached to buildings and other structures, or even to the tailpipes of gas-powered vehicles.

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A simple, cheap material for carbon capture, perhaps from tailpipes

Photo, posted June 10, 2006, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cleaning Up Forever Chemicals | Earth Wise

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PFAS, per- and polyfluoroalkyl substances, are chemical pollutants that threaten human health and ecosystem sustainability.  They are used in a wide range of applications including food wrappers and packaging, dental floss, firefighting foam, nonstick cookware, textiles, and electronics.  Over decades, these manufactured chemicals have leached into our soil, air, and water.  Chemical bonds in PFAS molecules are some of the strongest known, so the substances do not degrade easily in the environment.

Studies have shown that at certain levels, PFAS chemicals can be harmful to humans and wildlife and have been associated with a wide variety of health problems.

Currently, the primary way to dispose of PFAS chemicals is to burn them, which is an expensive multistep process.  Even trace levels are toxic, so when they occur in water in low amounts, they need to be concentrated in order to be destroyed.

Researchers at Texas A&M University have developed a novel bioremediation technology for cleaning up PFAS.  It uses a plant-derived material to absorb the PFAS which is then eliminated by microbial fungi that literally eat the forever chemicals.

The sustainable plant material serves as a framework to adsorb the PFAS.  That material containing the adsorbed PFAS serves as food for the fungus.  Once the fungus has eaten it, the PFAS is gone. 

The EPA has established a nationwide program to monitor the occurrence and levels of PFAS in public water systems and is considering adding PFAS threshold levels to drinking water standards.  If this happens, the technology developed at Texas A&M may become an essential part of municipal water systems.

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Texas A&M AgriLife develops new bioremediation material to clean up ‘forever chemicals’

Photo, posted August 10, 2013, courtesy of Mike Mozart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Better Way To Recycle Plastic | Earth Wise

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The current state of plastic recycling is not very effective.  Plastic recycling is only able to replace 15-20% of the fossil-fuel-derived raw material needed to produce society’s demand for plastic.

Researchers at Chalmers University in Sweden have now demonstrated how the carbon content in mixed waste could be used to replace all of the fossil raw materials in the production of new plastic.  In principle, their technology could completely eliminate the climate impact of plastic materials.

According to the researchers, there are enough carbon atoms in waste to meet the needs of all global plastic production.

The Chalmers process is based on thermochemical technology and involves heating waste to 1100-1500 degrees Fahrenheit.  The waste is thereby vaporized and when hydrogen is added, becomes a carbon-based substance that can replace the fossil-fuel building blocks of plastic.  The method does not require sorting the waste materials.  Different types of waste, such as old plastic products and even paper cups, with or without food residues, can be fed into the recycling reactors.  The researchers are now developing the techniques required to utilize their recycling technology in the same factories in which plastic products are currently being made from fossil oil or gas.

The principle of the process is inspired by the natural carbon cycle in which plants break down into carbon dioxide when they wither and die, and then photosynthesis uses carbon dioxide and solar energy to grow new plants.

Producing new plastics would no longer require petroleum or other fossil fuels as raw materials.  If the energy needed to drive the recycling reactors is taken from renewable sources, plastics could become the basis of a sustainable and circular economy.

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Pioneering recycling turns mixed waste into premium plastics with no climate impact

Photo, posted August 10, 2013, courtesy of Lisa Risager via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Storing Sunshine To Make Electricity On Demand | Earth Wise

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Researchers at Chalmers University in Sweden have developed an entirely new way of capturing and storing energy from sunlight.  The system is called the Molecular Thermal Energy Storage System or MOST.  It is based on a specially designed molecule that changes shape when it is exposed to sunshine.

The molecule is composed of carbon, hydrogen, and nitrogen.  When sunlight hits it, it changes into an energy-rich isomer – a molecule made up of the same atoms but arranged together in a different way.  That isomer is stable and can be stored for many years.  When a specially designed catalyst is applied, the stored energy is released in the form of heat and the molecule returns to its original form and can be reused. 

The Chalmers researchers sent some of the energy-laden isomer to researchers in China who used it to operate a micron-thin thermoelectric generator, which used the heat released by the isomer material to generate electricity.  The generator is an ultra-thin chip that could be integrated into electronics such as headphones, smart watches, and telephones.  It is currently only at the proof-of-concept stage, but the results are quite promising.  The integration with the MOST technology provides a way that solar energy can generate electricity regardless of weather, time of day, season, or geographical location.  The results of the study were recently published in the journal Cell Reports Physical Science.

In effect, for this demonstration, Swedish sunshine was sent to the other side of the world and converted into electricity in China. The ultimate goal of this research is to create self-charging electronics that uses stored solar energy on demand.

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Converting solar energy to electricity on demand

Photo, posted March 11, 2013, courtesy of Steve Slater via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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